chore: add charm readme

charm/README.md

@@ -0,0 +1,35 @@
+# The Charm for the charmhub.io website
+
+This charm was created using the [PaaS App Charmer](https://juju.is/docs/sdk/paas-charm)
+
+## Local development
+
+To work on this charm locally, you first need to set up an environment, follow [this section](https://juju.is/docs/sdk/write-your-first-kubernetes-charm-for-a-flask-app#heading--set-things-up) of the tutorial.
+
+Then, you can run the following command to pack and upload the rock:
+
+```bash
+rockcraft pack
+rockcraft.skopeo --insecure-policy copy --dest-tls-verify=false oci-archive:charmhub-io*.rock docker://localhost:32000/charmhub-io:1
+```
+
+You can deploy the charm locally with:
+
+```bash
+cd charm
+charmcraft fetch-libs
+charmcraft pack
+juju deploy ./*.charm --resource flask-app-image=localhost:32000/charmhub-io:1
+```
+
+once `juju status` reports the charm as `active`, you can test the webserver:
+
+```bash
+curl {IP_OF_CHARMHUB_IO_UNIT}:8000
+```
+
+<!-- TODO: Add a section for connecting using browser -->
+
+## Design Decisions:
+- To keep the codebase clean and charm libraries updated, they are only fetched before packing the charm in the [Github Actions workflow](https://github.com/canonical/charmhub.io/blob/main/.github/workflows/publish_charm.yaml#L25).
+- As all our work is open source, the charm is publicly available on [Charmhub](https://charmhub.io/charmhub-io), the rock image is also included as a resource. This significantly simplifies deployment.